Reaction injection molded polyurethanes are well known in the art as described in a paper entitled "THE BAYFLEX 110 SERIES-THE NEW GENERATION OF RIM MATERIALS", by W. A. Ludwico and R. P. Taylor presented at the SOCIETY OF AUTOMOTIVE ENGINEERS PASSENGER CAR MEETING, Detroit, Mich., Sept. 26-30, 1977; a paper entitled "THE PROPERTIES OF HIGH MODULUS RIM URETHANES", by R. M. Gerkin and F. E. Critchfield presented at the above meeting; British Pat. No. 1,534,258 titled "PROCESS FOR THE PRODUCTION OF ELASTOMERIC POLYURETHANE-POLYUREA MOULDED PRODUCTS HAVING A COMPACT SURFACE SKIN" and a book by F. Melvin Sweeny entitled INTRODUCTION TO REACTION INJECTION MOLDING, Technomics, Inc., 1979.
These systems employ, as chain extenders, diols, aromatic amines, cyanoethylated polyoxyalkylene amines and mixtures thereof.
It has been thought that as a general rule the aliphatic amines are too fast to be suitably employed in RIM urethane applications. We previously disclosed in our allowed copending application Ser. No. 114,803, filed Jan. 24, 1980, now U.S. Pat. No. 4,269,945 issued May 26, 1981, entitled "REACTION INJECTION MOLDED POLYURETHANES EMPLOYING ALIPHATIC AMINE CHAIN EXTENDERS" that certain quantities of aliphatic amines enhance certain properties such as one or more of those selected from, for example, flexural modulus, impact strength, tear strength, heat resistance and the like can be improved by their use in such RIM urethane systems usually without an unacceptable reduction in other properties of the polymer.
Since the properties of the resultant polyurethanes can be varied depending upon the ratio of primary aliphatic amine containing material to low molecular weight hydroxyl containing material and/or aromatic amine-containing material, the composition provides a means for varying the properties without having a multiplicity of compositions i.e., by having a composition which can be employed to prepare polyurethanes of varying properties by blending therewith the desired quantity of low molecular weight hydroxyl-containing material and/or aromatic amine-containing material and optionally additional quantities of relatively high molecular weight polyol and thereafter reacting such blend or as separate streams with a polyisocyanate and other optional components if desired.